1. Field of the Invention
The present invention relates to an exhaust gas purification device, and more particularly to an exhaust gas purification device in which a coating structure thereof is improved so as to sustain its normal purification efficiency.
2. Description of Related Art
Generally, the exhaust system of an engine exhausts exhaust gas to a rear of a vehicle and reduces exhaust noise.
Lately, a catalyst device has been used so as to purify the exhaust gas and transform harmful exhaust gas to harmless carbon dioxide and water.
Particularly, the catalyst device reduces hydrocarbon, carbon monoxide, and nitrogen oxide (NOx). Also, the catalyst device filters or burns particulate materials.
Generally, a catalyst filter mounted in the exhaust gas purification device has channels that are formed in a flow direction of the exhaust gas.
Further, the inlet of at least one among the channels is closed and the outlet thereof is opened, the inlet of at least another one among the channels is closed and the outlet thereof is opened, and the closed portions are alternatively disposed.
And, a catalytic particulate filter (CPF) among the catalyst devices is applied, wherein the particulate materials (PM) burn to be transformed to soot therein.
The soot is trapped and accumulated inside the catalytic particulate filter (CPF) such that the generating amount of NO2 is reduced and NOx purification efficiency of a selective catalyst reduction device is also reduced.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.